This invention relates generally to a system and method for providing an adaptive bandwidth system and method for a broadcast system and in particular, to a system and method for allocating bandwidth over a broadcast type system in response to downstream end user behavior.
Typical broadcast type systems, such as television systems and cable systems, broadcast the same signal to all service nodes and/or subscribers. These typical systems are known as broadcast systems because a single identical signal is transmitted at all times regardless of whether it is being used by any end user. It is desirable for broadcast systems, such as cable television systems, to be able to have a digital packet switched system so that system bandwidth is only used for services actually being used by end users.
There are various different systems that attempt to provide some features of a switched system to broadcast systems. For example, one patent, assigned to Stanford University, describes a method of tracking and targeting a demographically-defined audience in a cable system in which one or more different channels containing advertisements permit advertisements to be targeted to a particular group of customers. The patent does not describe, however, a digital data switched system for a broadcast system. Another patent, assigned to Zenith, discloses a method for multiplexing compressed video and auxiliary data on the same TV transmission system. The system includes a feedback mechanism that allows the multiplexor to the buffering rates of the components of the signal in order to maintain certain quality levels. Again, this system is not a digital data switched network. Yet another patent, assigned to Lucent, describes a method for multiplexing data services across multiple TV transmission channels. In this method, the maximum data levels are fixed on each channel but a bandwidth manager dynamically tracks bandwidth usage on the channels and has the ability to determine on which channel(s) any additional traffic will be located.
A digital data switched network may provide a broadcast system with many advantages and capabilities not now available with a broadcast system. For example, the signals, including both programming signals and advertisements, being sent to each subscriber or service node may be more specifically targeted to each subscriber or service node. In addition, the bandwidth being allocated to any single service may be increased, decreased or reduced to zero for some period of time. The digital switched system also permits individual multiplexes of signals to be sent to each service node. Thus, it is desirable to provide a digital data switched network for typical broadcast systems and it is to this end that the present invention is directed.